(1) Field of the Invention
The present invention relates to the field of preparation of liquid samples with a view to their analysis.
The present invention relates more particularly to a method and a device for drawing and mixing liquid samples originating from at least n (n≧2) different containers.
(2) Prior Art
Such methods and/or devices for drawing and mixing liquid product samples are already known in the prior art.
In the United States document US H1960 H, a method and a device are proposed which are intended to analyse donations of blood or plasma with a view to detecting the specific donations having contamination by a virus, greater than a pre-established level. The method comprises a first step consisting of forming containers of unitary samples, sealed separately and interconnected, using a flexible hollow tubing segment connected to a container of donations of fluid. It is therefore a matter of drawing n times a given volume of a sample originating from a container. This step is repeated for n containers of donations of biological liquids. Advantageously, each container of samples is formed in order to contain approximately 0.02 to 0.5 ml of blood or plasma. A second step then consists of transferring identical volumes of a sample obtained in step 1 into a mixing container. At this step, a sample from the n containers obtained is drawn.
Thus, according to one example embodiment of the invention described in US H1960 H, the drawing and mixing device comprises a central hollow tubular collection container connected to a vacuum source, and under which needles are connected for automatic drawing of blood or plasma from the unitary containers. Thus, once the needles are disposed to pierce through the unitary containers containing the blood or plasma samples, the vacuum is applied to the container so that the blood or plasma samples rise up through the needles into the container. Advantageously, in order to prevent any contamination, the drawing devices (needles for example) are sterilised or replaced so that cleaned or sterile devices are used between each mixture formed.
Also proposed in the U.S. Pat. No. 5,364,526 is a system making it possible to conduct, into a receiving or transfer container, biological fluid disposed in independent containers (at least two independent containers). This transfer takes place via a grouping device consisting of a plurality of pieces of tubing, said grouping device being in communication respectively with each of the independent containers and the receiving container. Advantageously, the elements constituting the system are disposed in a vertical arrangement, the independent containers being disposed above the receiving container. Once full, the receiving container is hermetically sealed and separated from the system, without air being introduced into said container. Advantageously, the system is a sterile system.
However, the method and system described in the aforementioned documents have drawbacks.
In particular, the method described by US H1960 H discloses a discontinuous method. It emerges in fact that, prior to the drawing of the samples, it is necessary to place pre-formed samples in an apparatus in order to allow the drawing of each of the pre-formed samples. The result is therefore a tedious and long method.
As regards the system described in U.S. Pat. No. 5,364,526, this, through its construction, offers no guarantee of drawing sterility. This is because the piece of tubing originating from each independent container is in contact with at least one other piece of tubing originating from another independent container. Such a system therefore does not allow drawings from containers to be isolated from one another.